DIY Network

Repairing Grout Patch and repair missing grout to prevent further damage. From "DIY Weekend" episode DIYW-216

Do you have grout between tiles that's either cracked or missing? You don't want to ignore the problem –– if water gets in there, it can loosen more of the grout and possibly the tile. Also, it is a perfect place for mold and mildew to move in. You don't need to be a professional tile installer to repair grout, you can do it yourself.

A grout removal tool or a screwdriver can be used.

For a basic grout repair, you will need:

grout removal tool
grout float
grout (premixed if you can find it to match your color)
bucket
rubber gloves
grout sponge
grout sealer

Throughly clear out all loose grout.

The first step is to remove the loose grout. Scratch away the grout using a grout removal tool. A screwdriver or the points of a can opener can also be used. Keep working until you are certain all the grout in the seam is solid and dry. Vacuum out all dust.

Smear the grout in at an angle.

Now you are ready to lay in the new grout. If you have a standard color grout you may be able to buy a premixed grout which is easiest for small fixes like this. But, if you have a colored grout, you're going to have to match the color correctly. Just put a little grout on the edge of the float and hold the float at a forty-five degree angle to push the grout gently into the crack. Be sure to move the float across the crack at an angle or you will drag the grout back out of the seam.

Wipe the excess off with a damp grout sponge. Let the grout dry for about four hours. A haze will form on the tile. After the grout is dry, go back and wipe the haze off.

Wait about twenty-four hours until the grout is completely dry and then apply a good sealer.